EP 0493074 A3 19930331 - VACUUM GAUGE
Title (en)
VACUUM GAUGE
Publication
Application
Priority
US 63437790 A 19901227
Abstract (en)
[origin: EP0493074A2] The present invention provides a vacuum gauge having two integrated circuits connected in a half bridge circuit to register subatmospheric gas pressure from a change in thermal gas conductivity. One of the integrated circuits serves to generate an electrical current proportional to the ambient temperature and a function of its power output conducted by the gas. The other of the integrated circuits acts as a reference to generate an electrical current proportional to ambient temperature. The half bridge circuit acts to subtract the currents so that subatmospheric pressure can be read on an ammeter as a function of gas thermal conductivity. <IMAGE>
IPC 1-7
IPC 8 full level
G01L 21/10 (2006.01); G01L 21/12 (2006.01)
CPC (source: EP US)
G01L 21/10 (2013.01 - EP US)
Citation (search report)
- [A] US 3884080 A 19750520 - CHAPMAN RONALD
- [A] EP 0071694 A1 19830216 - LEYBOLD HERAEUS GMBH & CO KG [DE]
- [A] US 4682503 A 19870728 - HIGASHI ROBERT E [US], et al
Designated contracting state (EPC)
DE FR GB IT
DOCDB simple family (publication)
US 5079954 A 19920114; DE 69110024 D1 19950629; DE 69110024 T2 19951123; EP 0493074 A2 19920701; EP 0493074 A3 19930331; EP 0493074 B1 19950524; JP H04278430 A 19921005; JP H0765945 B2 19950719
DOCDB simple family (application)
US 63437790 A 19901227; DE 69110024 T 19911223; EP 91311958 A 19911223; JP 34487591 A 19911226